Пример #1
0
    @Override
    public void onCompletion(CountedCompleter caller) {
      ScoreBuildHistogram sbh = (ScoreBuildHistogram) caller;
      // System.out.println(sbh.profString());

      final int leafk = _leafs[_k];
      int tmax = _tree.len(); // Number of total splits in tree K
      for (int leaf = leafk; leaf < tmax; leaf++) { // Visit all the new splits (leaves)
        DTree.UndecidedNode udn = _tree.undecided(leaf);
        //        System.out.println((_st._nclass==1?"Regression":("Class
        // "+_fr2.vecs()[_st._ncols].domain()[_k]))+",\n  Undecided node:"+udn);
        // Replace the Undecided with the Split decision
        DTree.DecidedNode dn = _st.makeDecided(udn, sbh._hcs[leaf - leafk]);
        //        System.out.println(dn +
        //                           "  > Split: " + dn._split + " L/R:" + dn._split._n0+" +
        // "+dn._split._n1);
        if (dn._split._col == -1) udn.do_not_split();
        else {
          _did_split = true;
          DTree.Split s = dn._split; // Accumulate squared error improvements per variable
          AtomicUtils.FloatArray.add(_improvPerVar, s.col(), (float) (s.pre_split_se() - s.se()));
        }
      }
      _leafs[_k] = tmax; // Setup leafs for next tree level
      int new_leafs = _tree.len() - tmax;
      _hcs[_k] = new DHistogram[new_leafs][ /*ncol*/];
      for (int nl = tmax; nl < _tree.len(); nl++) _hcs[_k][nl - tmax] = _tree.undecided(nl)._hs;
      if (_did_split) _tree._depth++;
    }
Пример #2
0
 // Find the column with the best split (lowest score).  Unlike RF, GBM
 // scores on all columns and selects splits on all columns.
 @Override
 public DTree.Split bestCol(UndecidedNode u, DHistogram[] hs) {
   DTree.Split best =
       new DTree.Split(-1, -1, false, Double.MAX_VALUE, Double.MAX_VALUE, 0L, 0L, 0, 0);
   if (hs == null) return best;
   for (int i = 0; i < hs.length; i++) {
     if (hs[i] == null || hs[i].nbins() <= 1) continue;
     DTree.Split s = hs[i].scoreMSE(i);
     if (s == null) continue;
     if (best == null || s.se() < best.se()) best = s;
     if (s.se() <= 0) break; // No point in looking further!
   }
   return best;
 }